Connection of Fill Tube to a Two-Phase Heat Dissipation Device

ABSTRACT

This invention discloses a cold-work method to connect the metal wall of a two-phase heat dissipation device with a fill tube. First, place the fill tube into a hole prepared in the wall, then push a squeezer slightly larger than the inner diameter of the fill tube to create permanent deformation and hence hermetical bonding thereof. Finally, draw out the squeezer to finish the cold work. This method simplifies the procedure and equipment by avoiding a relatively high-temperature soldering or brazing process.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

This invention relates to the installation of a fill tube in two-phase heat dissipation devices, such as flat plate heat pipes, loop heat pipes, capillary pumped loops, spray cooling devices, et al., which need to be evacuated and filled with working fluids.

(2) Brief Description of Related Art

The interior of two-phase heat dissipation devices, such as flat plate heat pipes, loop heat pipes, capillary pumped loops, spray cooling devices, et al., must be free from non-condensable gases. Therefore, hermetic sealing is required for the containers. Also, the connection between the container and the fill tube, through which evacuation and filling of the working fluid is performed carefully, must be hermetic. Afterwards, the sealing is completed by pinching off the fill tube. Conventionally, the hermetic connection between the container and the fill tube is handled by soldering, brazing, or welding. However, these methods are carried out at a relative high temperature working conditions. The procedure as well as the equipment is more complicated. Moreover, when the working temperature is above the anneal temperature, the rigidity of the container decreases seriously.

SUMMARY OF THE INVENTION

This invention disclosed a simple cold-work method for hermetic connection of the fill tube to the container at a relatively low temperature. Not only the rigidity of the container can be maintained, but also the cost can be reduced with simpler procedure and equipment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows step 1 of a first embodiment according to the present invention, a fill tube inserting into a hole on the wall of the container.

FIG. 2 shows step 2 of the first embodiment, a squeezer inserting into the fill tube.

FIG. 3 shows a different squeezer can be used according to the present invention.

FIG. 4 shows an interfacial layer can be inserted in between the connection surface before connection according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

A cold-work procedure to connect a fill tube to a container at a relatively low working temperature, or room temperature, is disclosed. Under this low temperature connection procedure, the rigidity of the container is maintained, and the cost is reduced with a simpler procedure and equipment.

FIG. 1 shows step 1 to put the fill tube 3 into a hole of the container wall 1 of a two-phase heat dissipation device. FIG. 2 shows step 2, when a squeezer 4 a is inserted into the fill tube 3. The front section 7 of a cylindrical fill tube 3 is inserted into a hole 2 in the metal container wall 1. The inner diameter of the hole 2 is slightly larger than the outer diameter of the front section 7 of the fill tube 3. The surfaces of the connecting parts should be cleaned beforehand. With the container wall 1 clamped with a fixer 5, a cylindrical squeezer 4 a having a diameter somewhat larger than the inner diameter of the front section 7 of the fill tube 3 is squeezed in to cause permanent plastic deformation of the front section of the fill tube 3 and hermetic connection between the fill tube 3 and the container wall 1, as shown in FIG. 2. Afterwards, the squeezer 4 a is withdrawn to finish the cold connection. Although not shown in FIG. 2, fixing of the fill tube 3 is needed as the squeezer is being squeezed in and withdrawn. The extension section 8 of the fill tube 3 has a larger diameter than that of the front section 7 for easy movement of the squeezer 4 a. Preferably, the fill tube 3 is annealed beforehand for easy deformation. The fixer 5 is used to clamp the container wall 1 and restrict its deformation so that only the front section 7 of the fill tube 3 is deformed. Spinning of the squeezer 4 a while it is moved in and out can make the process smoother.

FIG. 3 discloses a screw-type squeezer 4 b can be used alternatively. To screw the squeezer 4 b in causing permanent deformation and hermetic connection of the fill tube 3 into the container wall 1. Again, fixing of the fill tube 3 is needed as the squeezer is squeezed in and withdrawn.

FIG. 4 indicates that a layer of interfacial material 6 can be put between the surface of the front section 7 of the fill tube 3 and the container wall 1. The interfacial material 6 can be soft metals, such as lead, tin, or lead-tin alloy, etc.; soft non-metals, such as a plastic sheet, a rubber sheet, or a silicone rubber sheet, etc.; or binding agents, such as epoxy resin or silicone resin, etc.

While the preferred embodiments of the invention have been described, it will be apparent to those skilled in the art that various modifications may be made without departing from the spirit of the present invention. Such modifications are all within the scope of this invention. 

1. A method to hermetically connect a fill tube to the metal container wall of a two-phase heat dissipation device, comprises the steps of: (1) placing a front section of said fill tube into a hole prepared in said container wall; (2) forcing a squeezer with diameter somewhat larger than the inner diameter of said front section of said fill tube into said front section of said fill tube, to cause permanent plastic deformation of said fill tube; and (3) drawing out said squeezer.
 2. A method as describe in claim 1, wherein said squeezer is a cylindrical object.
 3. The method as describe in claim 1, wherein said squeezer is a screw-type cylindrical object.
 4. The method as describe in claim 1, wherein an interfacial material is added between the connecting surfaces of said fill tube and said container wall.
 5. The method as describe in claim 4, wherein said interfacial material is a deformable metal.
 6. The method as describe in claim 4, wherein said interfacial material is a deformable non-metal.
 7. The method as describe in claim 4, wherein said interfacial material is a binding agent. 